Abstract: Urban public art installations have the characteristics of non-standard shapes, high precision requirements, and multi-disciplinary collaboration. The traditional two-dimensional construction mode has the drawbacks of low visualization and weak precision control. In response to the pain points of difficult precision control, lack of mature digital construction system, and dependence on manual experience in the construction of non-standard art installations, this article introduces intelligent construction methods and explores technical solutions for digital construction of non-standard art installations. Using the "Guanying Liufang Garden" Fengguan Art Installation at the 32nd Guangzhou Garden Expo as a carrier, integrating Building Information Modeling (BIM) and Mixed Reality (MR) technologies, a digital construction loop of "prefabricated design BIM modeling MR rehearsal on-site assembly virtual real verification" is constructed. A digital twin model of non-standard components is proposed, and construction visualization and precision are achieved through BIM modeling, MR application, QR code positioning and other means. Practice has shown that building information modeling and mixed reality methods, using ± 1.5 cm as the installation deviation control standard, ultimately reduced the unqualified rate of installation deviation in this case to 1.24%, solving the problem of large installation deviation and artistic distortion caused by traditional construction of non-standard components relying on manual experience, and achieving high fidelity effect of artistic installations. The successful practice of this case has achieved a transformation from experience driven to data-driven construction. The constructed digital construction method can provide technical reference for the intelligent construction of non-standard art installations and practical basis for the digital transformation of landscape engineering.